Subtotal on product page

Hello,

Try to Add the code below to the functions.php file in your child theme:

add_action( 'woocommerce_after_add_to_cart_button', 'pk_product_price_recalculate' );

function pk_product_price_recalculate() {
    global $product;
    echo '<div id="subtot" style="display:inline-block;">Subtotal: <span></span></div>';
    $price = $product->get_price();
    $currency = get_woocommerce_currency_symbol();
    wc_enqueue_js("
        $('[name=quantity]').on('input change', function() { 
            var qty = $(this).val();
            var price = '" . esc_js( $price ) . "';
            var price_string = (price * qty).toFixed(2);
            $('#subtot > span').html('" . esc_js( $currency ) . "' + price_string);
        }).change();
    ");
}

Best Regards